What is "digital telephony"? To the authors, the term digital telephony denotes the technology used to provide a completely digital telecommunication system from end-to-end. This implies the use of digital technology from one end instru ment through transmission facilities and switching centers to another end instru ment. Digital telephony has become possible only because of the recent and on going surge of semiconductor developments, allowing microminiaturization and high reliability along with reduced costs. This book deals with both the future and the present. Thus, the first chapter is entitled, "A Network in Transition." As baselines, Chapters 2 and 11 provide the reader with the present status of teler-hone technology in terms of voice digiti zation as well as switching principles. The book is an outgrowth of the authors' consulting and teaching experience in the field since the early 1980s. The book has been written to provide both the engineering student and the practicing engineer a working knowledge of the prin ciples of present and future telecommunication systems based upon the use of the public switched network. Problems or discussion questions have been included at the ends of the chapters to facilitate the book's use as a senior-level or first year graduate-level course text. Numerous clients and associates of the authors as well as hundreds of others have provided useful information and examples for the text, and the authors wish to thank all those who have so contributed either directly or indirectly.

What is "digital telephony"? To the authors, the term digital telephony de notes the technology used to provide a completely digital point-to-point voice communication system from end to end. This implies the use of digital technol ogy from one end instrument through the transmission facilities and switching centers to another end instrument. Digital telephony has become possible only because of the recent and ongoing surge of semiconductor developments allowing microminiaturization and high reliability along with reduced costs. This book deals with both the future and the present. Thus, the first chapter is entitled, "A Network in Transition." As baselines, Chapters 2, 3, and 10 provide the reader with the present status of telephone technology in terms of voice digitization as well as switching principles. The book is an outgrowth of the authors' continuing engineering education course, "Digital Telephony," which they have taught since January, 1980, to attendees from business, industry, government, common carriers, and tele phony equipment manufacturers. These attendees come from a wide variety of educational backgrounds. but generally have the equivalent of at least a bachelor's degree in electrical engineering. The book has been written to provide both the engineering student and the practicing engineer a working knowledge of the principles of present and future voice communication systems based upon the use of the public switched network. Problems or discussion questions have been included at the ends of the chapters to facilitate the book's use as a senior level or first year graduate level course text.

Introduces all aspects of digital communications, emphasizing voice applications and digitization, digital transmission and switching, network synchronization, control and analysis. Non-technical in the traditional (analytical) sense of communications theory, it stresses the application and operational aspects of communications and system design. Topical discussions in this Second Edition explore new terminology, the advantages and disadvantages of using digital voice networks, the functions and uses of digital radio and fiber optical transmission systems and an analysis of traffic patterns in the digital communications network. New equations and traffic tables, a revised glossary of terms, an up-to-date bibliography and an expanded index enhance and complete this book.

This book explores issues posed by convergent voice and data networks, and considers future scenarios as Internet telephony continues to alter the communications landscape.

This book concerns digital communication. Specifically, we treat the transport of bit streams from one geographical location to another over various physical media, such as wire pairs, coaxial cable, optical fiber, and radio. We also treat multiple-access channels, where there are potentially multiple transmitters and receivers sharing a common medium. Ten years have elapsed since the Second Edition, and there have been remarkable advances in wireless communication, including cellular telephony and wireless local-area networks. This Third Edition expands treatment of communication theories underlying wireless, and especially advanced techniques involving multiple antennas, which tum the traditional single-input single-output channel into a multiple-input multiple-output (MIMO) channel. This is more than a trivial advance, as it stimulates many advanced techniques such as adaptive antennas and coding techniques that take advantage of space as well as time. This is reflected in the addition of two new chapters, one on the theory of MIMO channels, and the other on diversity techniques for mitigating fading. The field of error-control coding has similarly undergone tremendous changes in the past decade, brought on by the invention of turbo codes in 1993 and the subsequent rediscovery of Gallager's low-density parity-check codes. Our treatment of error-control coding has been rewritten to reflect the current state of the art. Other materials have been reorganized and reworked, and three chapters from the previous edition have been moved to the book's Web site to make room.